Steel-retainer.



C. A. HULTQUIST.

STEEL RETAINER.

. APPLICATION FILED JULY I7. 1916.

' 1,238,01 8 n Patented Aug. 21,

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CHARLES A. HULTQUIST, 0F LOS ANGELES, GALEFOBIMIA.

se ner-newsman.

Specificationof Letters Patent.

. Patented Aug. 21, 121?.

Application filed. m 11, 1916. Serial No. 108,579.

with pnematic hammers to provide some means for, limiting the movement of the drill steel when struck by the hammer when the steel is not against the rock or when a very soft seam of material is drilled into. These devices have been fairly satisfactory save for the fact that when a soft spot is encountered by the drill the hammer will drive it with great force and cause the drill steel collar to strike the retainer with sufficient force to damage the retainer. It is the principal object of this invention to provide cushion means for absorbing the violent shocks imparted by the drill s'oeel collar to the retainer and thereby prevent the excessive breakage which is now common.

Another object is to provide means whereby the retainer yoke may be detachably held in position around the drill and may be swung out of engagement with the drill steel and thus allow the removal thereof.

Another object is to provide simple means for completely removing the retainer yoke when occasion requires. I i

A further object is to provide a drill steel retainer which is compact and strong in 1ts construction and which will operate without great danger of its becoming broken m which case the broken parts may be readlly replaced.

Other objects will appear hereinafter.

The invention is illustrated in the accompanying drawings in which:

Figure 1 is a view in plan illustrating the drill steel retainer and showing the mounting blots as well as the hammer piston in section.

Fig. 2 is a view in side elevation illustrating the retainer as in use and with parts broken away to disclose the shock absorber construction.

Fig. 3 is a view in elevation illustrating the retainer as mounted upon the end of a pneumatic hammer and further illustratingby full and dotted line positionsthe manner of removing the retainer yoke.

Referring to the drawings more particularly, 10 indicates the casing of a pneumatic drill which is provided with a reciprocating piston formed at its end with a driving head 11. The head 11 extends from the end of the casing 10 and into a longitudinal bore 12 which is formed the length of a retainer case 14. It is to be noted that the drill and its case may be of any preferred construction so that the case-will accommodate the retainer which is the essence of the present invention.

The retainer case 14 is formed with outwardly extending ears 15 and 16 which permit bolts 17 and 18 to pass therethrough and into threaded engagement with the end of the hammer case'lO and in a manner to cause the bore 12 to register with the hammer head 11. The hammer headll extends a short distance Within the bore 12 and the shank 19 of a drill steel 20 extends from the opposite end to a point adjacent the end of the hammer head and in a manner so that the head will impart violent blows to the shank. The drill steel is formed with a collar 21 which is adapted to bear against the lower face of the retainer case when the drill steel is in its uppermost position and will limit the movement of the, drill steel by engagement with an encircling loop 22 formed at the end of a retainer yoke 23. The retainer yoke is formed with a pair of arms 24: and 25 which terminate with hook members 26. These members are provided with a throat 27 which is adapted to pass over a semi-circular engaging member 28 which is formed at the end of the eye-bolts 29 and 30 by means of which the yoke is yieldably supported.

The eye-bolts 29 and 30 are provided with heads 31 and 32 which are formed .with transversely disposed slotted openings 33 and 34 through which the hook members pass. The lower walls of thebolt heads are cut away adjacent theretainer case so that the configuration of the remaining portion of the wall willbe semi-circular, as particu larly illustrated in Fig. 3 of the drawings, the flat face of the semi-circular formation being opposite the transverse slot 33. The bolts 29 and 30 extend through cylindrical spring housings 35 and 36 which are provided with bores which extend parallel with v the central longitudinal bore 12 extending through the casing. Each of the bolts is surrounded by a helical spring 37 which is confined upon the bolt by means of washers 38 and nuts 39. The opposite ends of the springs bear upon the end wall of the spring housings and allow the bolts 29 and30 to be reciprocated therethrough as shock is delivered to the yoke and insures that this shock will be absorbed by means of the compression springs 37. While I have shown the spring housings as disposed diametrically opposite each other upon the retainer case 14, it may be found convenient to move them either side of the center of the case so that the yoke member will more adequately retain the drill steel within its bore and crowd it toward the center of the bore after the stroke has been delivered.

In operation, the yoke is attached to the eye-bolts or detached therefrom by compressing the members 24 and 25 together and passing the semi-circular portions of the bolt heads through, the throats of the hooks when the yoke is in the position indicated in dotted lines in Fig. 3. This can only be accomplished when the arms of the yoke are drawn toward each other as the semi-circular portions 28 are formed along the inner sides of the eye-bolt's- It will be observed that after the hooks have engaged the heads of the eye-bolts the yoke may be swung downwardly and, due to its angular formation, will spring into seats 40 formed in the case 14.31111 will allow the loop 22 to encircle the drill 20. The loop is of a diameter suflicient to retain the collar 21 of the drill steel and permit the steel from being driven therethrough.

When the steel is to be removed, the arms 24 and 25 may be sprung out of the recesses 40 and allow the yoke to swing out of engagement with the drill steel. In this manner the device will positively secure a drill steel in position and will insure that it may be readily removed therefrom.

The action of the drill steel within the retainer is similar to that of other retainers as long as the substance being drilled does not become excessively soft or a hole is struck, When these conditions are encountered the drill steel will be violently hammered against the loop 22 of the retainer yoke and the force transmitted thereby will be absorbed within the springs 37 around the eye-bolts. In this manner the yoke may be used indefinitely without danger of breakage and without the possibility of the steel being driven into a slip or crevice Wl'llCll is sometimes found in rock, as the excessive .forces will be absorbed within the springs of the device.

It will thus be seen that the drill steel retainer here provided will permit the insertion and removal of the drill steel therein and will satisfactorily absorb excessive shock imparted to the drill steel.

I claim:

1. A drill steel retainer, comprising a tubular retainer case, resiliently heldyoke bolts mounted upon said case, a yoke comprising a U-shaped member, a drill loop at its lower end, a drill adapted to be encircled by said loop, means upon said drill engageable with said loop for limiting rcciprocating movement thereof, and hook means whereby said yoke may be detachably mounted upon its yoke bolts.

- 2. A drill steel retainer, comprising a tubular retainer case, a pair of spring housmgs formed upon opposite sides of said case, springs in said housings, a drill steel adapted to be reciprocated through said tubular retainer case, an annular collar formed upon said drill steel, a yoke loop adapted to restrict the. outwardly reciprocating movement of said drill steel, oppositely disposed yoke arms secured to said loop and extending upwardly along opposite sides of the retainer case, yoke hooks'formed at the ends of said arms, a semi-circular eye-bolt portion adapted to pass through the throat of each of said hooks when the yoke is in a pos1t1on at rlght angles to the longitudinal center of the retainer case, and reciprocal bolts extending into the housings and engaged by the springs secured to said eyebolt portions whereby the yoke arms may be allowed resilient movement when struck by the annular collar upon the drill steel.

3. A. drill steel retainer, comprising a tubular retainer case, a drill steel adapted to reciprocate through said retainer case, a collar formed upon said drill steel, a yoke loop adapted to partially encircle said steel and lie 1n the path of travel of the collar, draw bolts mounted upon the opposite sides of said tubular casing, means whereby said loop will be resiliently supported by said bolts, hook means for detachably securing said loop in its operative position, and means whereby it may be removed from the bolts when swung to an inoperative position.

4. A drill steel retainer, comprising a re tainer casing, a pair of draw bolts disposed upon opposite sides of said casing, resilient supporting means therefor, a head formed upon each of said bolts and provided with an elongated eye, said head being formed with a cut-away portion along its end and adjacent the retainer casing, a drill steel retaining loop member, hooks formed upon the end of said member and adapted to pass into the eyes "when the cut-away portion Within the head is in register with the hook opening, and means whereby said loop may be swung to a locked position in relation to 10 the bolt heads and the retainer easing.

In testimony whereof I have signed my name to this specification.

CHARLES A. HULTQUIST. 

